(Fluent) NHibernate : One entity composed of fields from different tables

Question

Is there a way of writing an NHibernate mapping so that you can have an entity that is composed of fields from different DB tables?

For Example is I have a Person and Address table, I want address fields to appear in my person object.

I want an entity like this:

public class person
{
    public virtual Guid Key{get; set;}
    public virtual string Name {get; set;}
    public virtual string Age {get; set;}
    public virtual string Address1 {get; set;} //from address table
    public virtual string Address2 {get; set;} //from address table

}

Answer 1

I think here's what you need. Not sure about support on Fluent NHibernate part, as well as I'm not sure about the validity of this idea.

Answer 2

If you are using Fluent NHibernate you can use WithTable, as in this example:

public class PersonMap : ClassMap<Person>
{
  public PersonMap()
  {
    Id(x => x.Key, "[Key]"); // Explicitly specify escaped column name to 
                             // avoid problems with reserved words
    Map(x => x.Name);
    Map(x => x.Age);

    WithTable("Address", m =>
    {
      m.Map(x => x.Address1);
      m.Map(x => x.Address2);
    });
  }
}

Answer 3

You could also consider using a many-to-many table between Person and Address. In that case, it might make sense to have a property "Addresses" that can just hold a list of however many addresses you want.

You can do a mapping (or whatever collection mapping works best) with a mapping to accomplish this.